WordPress fatal error: how to solve the error when logging in to the background of the site to install the plugin theme?

Recently the Dropbox API stopped using long-lived access tokens.To comply with these new changes, BackWPup plugins must implement the use of refresh tokens, which can only be obtained when you re-authenticate.

log inWordPress backendIndicates that this site has encountered a fatal error

You have one or more BackWPup jobs that need to reauthenticate with Dropbox.

The Dropbox API is discontinuing long-lived access tokens. To conform to these new changes, we must implement the use of refresh tokens, which can only be fetched when you reauthenticate.

Please visit each job below and reauthenticate your Dropbox connection.

Since the WordPress backup plugin BackWPup uses the Dropbox API to automatically backup and synchronize to Dropbox, after logging in to Dropbox again for authentication, an error message similar to the following appears▼

• This site has encountered a fatal error, please check your site's administrative email for instructions.
• Learn more about troubleshooting WordPress.

How to fix WordPress fatal error?

After migrating my WordPress website, the homepage and backend are both blank. What should I do?

It is recommended to enable "WordPress debug mode" to troubleshoot WordPress.

How to enable WordPress debug mode?

1. Edit the "wp-config.php" file in the root directory of your WordPress site;
2. will"define('WP_DEBUG', false); ",change into"define('WP_DEBUG', true); "
3. After enabling WordPress debugging, refresh the error page, and the path and error message of the plugin or theme that caused the error will be displayed;
4. Rename the wrong plugin or theme, for example: wordpress-SeoPlugin error, rename it to "=wordpress-seo".

/**
* 开发者专用：WordPress调试模式
*
* 将这个值改为true，WordPress将显示所有用于开发的提示
* 强烈建议插件开发者在开发环境中启用WP_DEBUG
*
* 要获取其他能用于调试的信息，请访问Codex
*
* @link https://codex.wordpress.org/Debugging_in_WordPress
*/
define('WP_DEBUG', true);
//define('WP_DEBUG', false);

• Finally "define('WP_DEBUG', false); "modified back"define('WP_DEBUG', false); . "

After refreshing the error page, the plugin prompt message that caused the WordPress error will be displayed▼

Strict Standards: Redefining already defined constructor for class PluginCentral in /home/eloha/public_html/etufo.org/wp-content/plugins/plugin-central/plugin-central.class.php on line 13

The initial assessment is that the fatal error in WordPress is caused by a WordPress plugin . Therefore, it is necessary to first record which WordPress plugin is causing the error message, and then eliminate them one by one.

Troubleshooting Renaming a WordPress Plugin Encountered a Fatal Error

Step 1:Press CRRL + F to search for "/plugins/"

• Highlight Quick Find on web pages with "/plugins/"path of the wrong plugin.

Step 2: Record the WordPress plugins that are causing the error message.

Record the following WordPress plugins with error messages:

• auto-tag-slug
• plugin-central
• contact-form-7
• rejected-wp-keyword-link-rejected

Step 3: Log in to your WordPress website space via FTP

Step 4: Rename all faulty WordPress plugins ▼

• Rename all current error WordPress plugins, e.g. "contact-form-7", renamed to "=contact-form-7"
• That is, add the symbol in front of the WordPress plugin name=

Step 5: Test refresh of the error page

• See if it's back to normal?
• If yes, then rename the WordPress plugins one by one and see if it goes back to normal?

Step 6: Rename each plugin back to its original name in the WordPress plugin.

• For example, rename the plugin to "=contact-form-7" just now, and now rename it back to "contact-form-7".

Step 7: Locate the WordPress plugin causing the error and suspend its use.

• When renaming back to a WordPress plugin, a fatal error message appears after refreshing the webpage, which means that the WordPress plugin has caused a fatal error and needs to be suspended.
• For example, if the contact-form-7 plug-in is renamed back to "contact-form-7", and a fatal error message appears after refreshing the webpage, it can be determined that it is the fatal error caused by the contact-form-7 plug-in.
• This will allow you to quickly troubleshoot and find WordPress plugins with fatal errors on your WordPress site.

Step 8: Turn off WordPress debug mode

Edit the "wp-config.php" file and change "define('WP_DEBUG', true );" back to "define('WP_DEBUG', false );".